Probably going to more or less repeat what everyone has said in regards to choices but:

NJPW: If you can get past the language barrier this is going to be your best bet considering your criteria with great wrestling, some feuds, and belts that seem to mean something. Everyone has mentioned that the in-ring product is top notch but the production quality is at an equally high level. It looks like an important wrestling promotion and not a lower tier one.
CHIKARA: This is not a promotion for everyone. Best way to describe Chikara is a comic book or cartoon come to life. The storylines a great, probably better than any other promotion you'll find. Chikara isn't quite known for delivering MOTYC on every show but every show is at the very least fun and has something to offer so when you do get a MOTYC its more of a cherry on top. The tag belts probably seem more important in this promotion than any other with the rules placed upon them where you must beat 3 teams without losing to get a title shot.
PWG: Less storylines than other promotions, though not non-existent either, PWG is probably delivering the consistently high-quality in-ring product of any promotion in America. Shows are fun but not in a Chikara way. Action is blistering a lot of the times. PWG's crowd in Reseda,CA is probably the best in the country. Maybe the title belts aren't always the most important but I personally feel that the wrestlers that the straps are what they are going for a lot of the time.